Spatial Analysis and Risk Assessment of Soil Heavy Metal Pollution in the Xishimen Iron Mining Area of Hebei Province

Abstract

BACKGROUND Heavy metal pollution in the soil of mining areas is a serious threat to the ecological environment and the health of surrounding residents, and it is of great significance to effectively supervise it. The Xishimen iron deposit in Hebei Province is a large magnetite deposit in the Hanxing area. Comprehensive research on soil heavy metal pollution in this mining area is urgently needed. OBJECTIVES To evaluate soil heavy metal pollution in the Xishimen iron mining area in Hebei Province. METHODS The No.1 mining area of the Xishimen iron deposit was selected as the research object. ICP-MS was used to determine the heavy metal content. The exceedance rate, pollution sources and spatial distribution characteristics of heavy metals were obtained by descriptive statistical analysis, multivariate statistical analysis and spatial interpolation analysis, and the pollution risk was evaluated by combining the single factor pollution index, Nemero comprehensive pollution index and potential ecological hazard index. RESULTS Descriptive statistical analysis showed that the exceedance rate of Co in the mining area was 75.83%, indicating heavy pollution, while the exceedance rates of Cu, Cd and As were 14.70%, 21.40% and 13.29%, indicating moderate to light pollution. The exceedance rates of Cr, Ni, Zn, Pb and Hg were less than 5%, which were light pollution. The multivariate statistical analysis showed that Cr, Ni, Zn, Cd, As and Pb were from the natural weathering environmental pollution in the mineralized area, and Co and Cu were from the anthropogenic environmental pollution caused by mining production and fertilizer use. Hg came from the local pollution caused by human factors. Spatial interpolation analysis showed that the nine heavy metals had a high distribution in the open pit mining area on both sides of the Mahui River and a low distribution in the rivers and residential areas. The Nemero comprehensive pollution index of heavy metals in the study area was 13.49, and the comprehensive ecological risk index was 55.50. CONCLUSIONS The results indicate that there is Hg, Co, and Cu pollution caused by human factors in the mining area, which needs to be addressed. The heavy metal pollution in this area is serious but the ecological risk is still in a controllable range.

Keywords

• mining area
• heavy metals in soil
• inductively coupled plasma-mass spectrometry
• statistical analysis
• spatial analysis
• pollution risk evaluation